/* DHT.c
*
* An implementation of the DHT as seen in http://wiki.tox.im/index.php/DHT
*
* Copyright (C) 2013 Tox project All Rights Reserved.
*
* This file is part of Tox.
*
* Tox is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* Tox is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with Tox. If not, see .
*
*/
/*----------------------------------------------------------------------------------*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include "DHT.h"
#include "network.h"
#include "ping.h"
#include "misc_tools.h"
#include "util.h"
/* The number of seconds for a non responsive node to become bad. */
#define BAD_NODE_TIMEOUT 70
/* The max number of nodes to send with send nodes. */
#define MAX_SENT_NODES 8
/* Ping timeout in seconds */
#define PING_TIMEOUT 5
/* The timeout after which a node is discarded completely. */
#define Kill_NODE_TIMEOUT 300
/* Ping interval in seconds for each node in our lists. */
#define PING_INTERVAL 60
/* Ping interval in seconds for each random sending of a get nodes request. */
#define GET_NODE_INTERVAL 10
#define MAX_PUNCHING_PORTS 128
/* Interval in seconds between punching attempts*/
#define PUNCH_INTERVAL 10
#define NAT_PING_REQUEST 0
#define NAT_PING_RESPONSE 1
/* Used in the comparison function for sorting lists of Client_data. */
typedef struct {
Client_data c1;
Client_data c2;
} ClientPair;
/* Create the declaration for a quick sort for ClientPair structures. */
declare_quick_sort(ClientPair);
/* Create the quicksort function. See misc_tools.h for the definition. */
make_quick_sort(ClientPair);
Client_data *DHT_get_close_list(DHT *dht)
{
return dht->close_clientlist;
}
/* Compares client_id1 and client_id2 with client_id.
*
* return 0 if both are same distance.
* return 1 if client_id1 is closer.
* return 2 if client_id2 is closer.
*/
int id_closest(uint8_t *id, uint8_t *id1, uint8_t *id2)
{
size_t i;
uint8_t distance1, distance2;
for (i = 0; i < CLIENT_ID_SIZE; ++i) {
distance1 = abs(((int8_t *)id)[i] ^ ((int8_t *)id1)[i]);
distance2 = abs(((int8_t *)id)[i] ^ ((int8_t *)id2)[i]);
if (distance1 < distance2)
return 1;
if (distance1 > distance2)
return 2;
}
return 0;
}
/* Turns the result of id_closest into something quick_sort can use.
* Assumes p1->c1 == p2->c1.
*/
static int client_id_cmp(ClientPair p1, ClientPair p2)
{
int c = id_closest(p1.c1.client_id, p1.c2.client_id, p2.c2.client_id);
if (c == 2)
return -1;
return c;
}
static int id_equal(uint8_t *a, uint8_t *b)
{
return memcmp(a, b, CLIENT_ID_SIZE) == 0;
}
static int is_timeout(uint64_t time_now, uint64_t timestamp, uint64_t timeout)
{
return timestamp + timeout <= time_now;
}
/* Check if client with client_id is already in list of length length.
* If it is then set its corresponding timestamp to current time.
* If the id is already in the list with a different ip_port, update it.
* TODO: Maybe optimize this.
*
* return True(1) or False(0)
*/
static int client_or_ip_port_in_list(Client_data *list, uint32_t length, uint8_t *client_id, IP_Port ip_port)
{
uint32_t i;
uint64_t temp_time = unix_time();
uint8_t candropipv4 = 1;
if (ip_port.ip.family == AF_INET6) {
uint8_t ipv6cnt = 0;
/* ipv6: count how many spots are used */
for (i = 0; i < length; i++)
if (list[i].ip_port.ip.family == AF_INET6)
ipv6cnt++;
/* more than half the list filled with ipv6: block ipv4->ipv6 overwrite */
if (ipv6cnt > length / 2)
candropipv4 = 0;
}
/* if client_id is in list, find it and maybe overwrite ip_port */
for (i = 0; i < length; ++i)
if (id_equal(list[i].client_id, client_id)) {
/* if we got "too many" ipv6 addresses already, keep the ipv4 address */
if (!candropipv4 && (list[i].ip_port.ip.family == AF_INET))
return 1;
/* Refresh the client timestamp. */
list[i].timestamp = temp_time;
list[i].ip_port = ip_port;
return 1;
}
/* client_id not in list yet: find ip_port to overwrite */
for (i = 0; i < length; ++i)
if (ipport_equal(&list[i].ip_port, &ip_port)) {
/* Refresh the client timestamp. */
list[i].timestamp = temp_time;
memcpy(list[i].client_id, client_id, CLIENT_ID_SIZE);
return 1;
}
return 0;
}
/* Check if client with client_id is already in node format list of length length.
*
* return 1 if true.
* return 2 if false.
*/
static int client_in_nodelist(Node_format *list, uint32_t length, uint8_t *client_id)
{
uint32_t i;
for (i = 0; i < length; ++i) {
if (id_equal(list[i].client_id, client_id))
return 1;
}
return 0;
}
/* return friend number from the client_id.
* return -1 if a failure occurs.
*/
static int friend_number(DHT *dht, uint8_t *client_id)
{
uint32_t i;
for (i = 0; i < dht->num_friends; ++i) {
if (id_equal(dht->friends_list[i].client_id, client_id))
return i;
}
return -1;
}
/*
* helper for get_close_nodes(). argument list is a monster :D
*/
static void get_close_nodes_inner(DHT *dht, uint8_t *client_id, Node_format *nodes_list,
sa_family_t sa_family, Client_data *client_list, uint32_t client_list_length,
time_t timestamp, int *num_nodes_ptr)
{
int num_nodes = *num_nodes_ptr;
int tout, inlist, ipv46x, j, closest;
uint32_t i;
for (i = 0; i < client_list_length; i++) {
Client_data *client = &client_list[i];
tout = is_timeout(timestamp, client->timestamp, BAD_NODE_TIMEOUT);
inlist = client_in_nodelist(nodes_list, MAX_SENT_NODES, client->client_id);
#ifdef TOX_ENABLE_IPV6
IP *client_ip = &client->ip_port.ip;
/*
* Careful: AF_INET isn't seen as AF_INET on dual-stack sockets for
* our connections, instead we have to look if it is an embedded
* IPv4-in-IPv6 here and convert it down in sendnodes().
*/
sa_family_t ip_treat_as_family = client_ip->family;
if ((dht->c->lossless_udp->net->family == AF_INET6) &&
(client_ip->family == AF_INET6)) {
/* socket is AF_INET6, address claims AF_INET6:
* check for embedded IPv4-in-IPv6 */
if (IN6_IS_ADDR_V4MAPPED(&client_ip->ip6.in6_addr))
ip_treat_as_family = AF_INET;
}
ipv46x = !(sa_family == ip_treat_as_family);
#else
ipv46x = !(sa_family == AF_INET);
#endif
/* If node isn't good or is already in list. */
if (tout || inlist || ipv46x)
continue;
if (num_nodes < MAX_SENT_NODES) {
memcpy(nodes_list[num_nodes].client_id,
client->client_id,
CLIENT_ID_SIZE );
nodes_list[num_nodes].ip_port = client->ip_port;
num_nodes++;
} else {
/* see if node_list contains a client_id that's "further away"
* compared to the one we're looking at at the moment, if there
* is, replace it
*/
for (j = 0; j < MAX_SENT_NODES; ++j) {
closest = id_closest( client_id,
nodes_list[j].client_id,
client->client_id );
/* second client_id is closer than current: change to it */
if (closest == 2) {
memcpy( nodes_list[j].client_id,
client->client_id,
CLIENT_ID_SIZE);
nodes_list[j].ip_port = client->ip_port;
break;
}
}
}
}
*num_nodes_ptr = num_nodes;
}
/* Find MAX_SENT_NODES nodes closest to the client_id for the send nodes request:
* put them in the nodes_list and return how many were found.
*
* TODO: For the love of based make
* this function cleaner and much more efficient.
*/
static int get_close_nodes(DHT *dht, uint8_t *client_id, Node_format *nodes_list, sa_family_t sa_family)
{
time_t timestamp = unix_time();
int num_nodes = 0, i;
get_close_nodes_inner(dht, client_id, nodes_list, sa_family,
dht->close_clientlist, LCLIENT_LIST, timestamp, &num_nodes);
for (i = 0; i < dht->num_friends; ++i)
get_close_nodes_inner(dht, client_id, nodes_list, sa_family,
dht->friends_list[i].client_list, MAX_FRIEND_CLIENTS,
timestamp, &num_nodes);
return num_nodes;
}
/* Replace first bad (or empty) node with this one.
*
* return 0 if successful.
* return 1 if not (list contains no bad nodes).
*/
static int replace_bad( Client_data *list,
uint32_t length,
uint8_t *client_id,
IP_Port ip_port )
{
uint32_t i;
uint64_t temp_time = unix_time();
uint8_t candropipv4 = 1;
if (ip_port.ip.family == AF_INET6) {
uint32_t ipv6cnt = 0;
/* ipv6: count how many spots are used */
for (i = 0; i < length; i++)
if (list[i].ip_port.ip.family == AF_INET6)
ipv6cnt++;
/* more than half the list filled with ipv6: block ipv4->ipv6 overwrite */
if (ipv6cnt > length / 2)
candropipv4 = 0;
}
for (i = 0; i < length; ++i) {
/* If node is bad */
Client_data *client = &list[i];
if ((candropipv4 || (client->ip_port.ip.family == AF_INET6)) &&
is_timeout(temp_time, client->timestamp, BAD_NODE_TIMEOUT)) {
memcpy(client->client_id, client_id, CLIENT_ID_SIZE);
client->ip_port = ip_port;
client->timestamp = temp_time;
ip_reset(&client->ret_ip_port.ip);
client->ret_ip_port.port = 0;
client->ret_timestamp = 0;
return 0;
}
}
return 1;
}
/* Sort the list. It will be sorted from furthest to closest.
* Turns list into data that quick sort can use and reverts it back.
*/
static void sort_list(Client_data *list, uint32_t length, uint8_t *comp_client_id)
{
Client_data cd;
ClientPair pairs[length];
uint32_t i;
memcpy(cd.client_id, comp_client_id, CLIENT_ID_SIZE);
for (i = 0; i < length; ++i) {
pairs[i].c1 = cd;
pairs[i].c2 = list[i];
}
ClientPair_quick_sort(pairs, length, client_id_cmp);
for (i = 0; i < length; ++i)
list[i] = pairs[i].c2;
}
/* Replace the first good node that is further to the comp_client_id than that of the client_id in the list */
static int replace_good( Client_data *list,
uint32_t length,
uint8_t *client_id,
IP_Port ip_port,
uint8_t *comp_client_id )
{
sort_list(list, length, comp_client_id);
uint8_t candropipv4 = 1;
if (ip_port.ip.family == AF_INET6) {
uint32_t i, ipv6cnt = 0;
/* ipv6: count how many spots are used */
for (i = 0; i < length; i++)
if (list[i].ip_port.ip.family == AF_INET6)
ipv6cnt++;
/* more than half the list filled with ipv6: block ipv4->ipv6 overwrite */
if (ipv6cnt > length / 2)
candropipv4 = 0;
}
int8_t replace = -1;
uint32_t i;
if (candropipv4) {
/* either we got an ipv4 address, or we're "allowed" to push out an ipv4
* address in favor of an ipv6 one
*
* because the list is sorted, we can simply check the client_id at the
* border, either it is closer, then every other one is as well, or it is
* further, then it gets pushed out in favor of the new address, which
* will with the next sort() move to its "rightful" position
*
* CAVEAT: weirdly enough, the list is sorted DESCENDING in distance
* so the furthest element is the first, NOT the last (at least that's
* what the comment above sort_list() claims)
*/
if (id_closest(comp_client_id, list[0].client_id, client_id) == 2)
replace = 0;
} else {
/* ipv6 case without a right to push out an ipv4: only look for ipv6
* addresses, the first one we find is either closer (then we can skip
* out like above) or further (then we can replace it, like above)
*/
for (i = 0; i < length; i++) {
Client_data *client = &list[i];
if (client->ip_port.ip.family == AF_INET6) {
if (id_closest(comp_client_id, list[i].client_id, client_id) == 2)
replace = i;
break;
}
}
}
if (replace != -1) {
#ifdef DEBUG
assert(replace >= 0 && replace < length);
#endif
Client_data *client = &list[replace];
memcpy(client->client_id, client_id, CLIENT_ID_SIZE);
client->ip_port = ip_port;
client->timestamp = unix_time();
ip_reset(&client->ret_ip_port.ip);
client->ret_ip_port.port = 0;
client->ret_timestamp = 0;
return 0;
}
return 1;
}
/* Attempt to add client with ip_port and client_id to the friends client list
* and close_clientlist.
*/
void addto_lists(DHT *dht, IP_Port ip_port, uint8_t *client_id)
{
uint32_t i;
/* convert IPv4-in-IPv6 to IPv4 */
if ((ip_port.ip.family == AF_INET6) && IN6_IS_ADDR_V4MAPPED(&ip_port.ip.ip6.in6_addr)) {
ip_port.ip.family = AF_INET;
ip_port.ip.ip4.uint32 = ip_port.ip.ip6.uint32[3];
}
/* NOTE: Current behavior if there are two clients with the same id is
* to replace the first ip by the second.
*/
if (!client_or_ip_port_in_list(dht->close_clientlist, LCLIENT_LIST, client_id, ip_port)) {
if (replace_bad(dht->close_clientlist, LCLIENT_LIST, client_id, ip_port)) {
/* If we can't replace bad nodes we try replacing good ones. */
replace_good(dht->close_clientlist, LCLIENT_LIST, client_id, ip_port,
dht->c->self_public_key);
}
}
for (i = 0; i < dht->num_friends; ++i) {
if (!client_or_ip_port_in_list(dht->friends_list[i].client_list,
MAX_FRIEND_CLIENTS, client_id, ip_port)) {
if (replace_bad(dht->friends_list[i].client_list, MAX_FRIEND_CLIENTS,
client_id, ip_port)) {
/* If we can't replace bad nodes we try replacing good ones. */
replace_good(dht->friends_list[i].client_list, MAX_FRIEND_CLIENTS,
client_id, ip_port, dht->friends_list[i].client_id);
}
}
}
}
/* If client_id is a friend or us, update ret_ip_port
* nodeclient_id is the id of the node that sent us this info.
*/
static void returnedip_ports(DHT *dht, IP_Port ip_port, uint8_t *client_id, uint8_t *nodeclient_id)
{
uint32_t i, j;
uint64_t temp_time = unix_time();
if (id_equal(client_id, dht->c->self_public_key)) {
for (i = 0; i < LCLIENT_LIST; ++i) {
if (id_equal(nodeclient_id, dht->close_clientlist[i].client_id)) {
dht->close_clientlist[i].ret_ip_port = ip_port;
dht->close_clientlist[i].ret_timestamp = temp_time;
return;
}
}
} else {
for (i = 0; i < dht->num_friends; ++i) {
if (id_equal(client_id, dht->friends_list[i].client_id)) {
for (j = 0; j < MAX_FRIEND_CLIENTS; ++j) {
if (id_equal(nodeclient_id, dht->friends_list[i].client_list[j].client_id)) {
dht->friends_list[i].client_list[j].ret_ip_port = ip_port;
dht->friends_list[i].client_list[j].ret_timestamp = temp_time;
return;
}
}
}
}
}
}
static int is_gettingnodes(DHT *dht, IP_Port ip_port, uint64_t ping_id)
{
uint32_t i;
uint8_t pinging;
uint64_t temp_time = unix_time();
for (i = 0; i < LSEND_NODES_ARRAY; ++i ) {
if (!is_timeout(temp_time, dht->send_nodes[i].timestamp, PING_TIMEOUT)) {
pinging = 0;
if (ping_id != 0 && dht->send_nodes[i].id == ping_id)
++pinging;
if (ip_isset(&ip_port.ip) && ipport_equal(&dht->send_nodes[i].ip_port, &ip_port))
++pinging;
if (pinging == (ping_id != 0) + ip_isset(&ip_port.ip))
return 1;
}
}
return 0;
}
/* Same but for get node requests. */
static uint64_t add_gettingnodes(DHT *dht, IP_Port ip_port)
{
uint32_t i, j;
uint64_t ping_id = ((uint64_t)random_int() << 32) + random_int();
uint64_t temp_time = unix_time();
for (i = 0; i < PING_TIMEOUT; ++i ) {
for (j = 0; j < LSEND_NODES_ARRAY; ++j ) {
if (is_timeout(temp_time, dht->send_nodes[j].timestamp, PING_TIMEOUT - i)) {
dht->send_nodes[j].timestamp = temp_time;
dht->send_nodes[j].ip_port = ip_port;
dht->send_nodes[j].id = ping_id;
return ping_id;
}
}
}
return 0;
}
/* Send a getnodes request. */
static int getnodes(DHT *dht, IP_Port ip_port, uint8_t *public_key, uint8_t *client_id)
{
/* Check if packet is going to be sent to ourself. */
if (id_equal(public_key, dht->c->self_public_key) || is_gettingnodes(dht, ip_port, 0))
return -1;
uint64_t ping_id = add_gettingnodes(dht, ip_port);
if (ping_id == 0)
return -1;
uint8_t data[1 + CLIENT_ID_SIZE + crypto_box_NONCEBYTES + sizeof(ping_id) + CLIENT_ID_SIZE + ENCRYPTION_PADDING];
uint8_t plain[sizeof(ping_id) + CLIENT_ID_SIZE];
uint8_t encrypt[sizeof(ping_id) + CLIENT_ID_SIZE + ENCRYPTION_PADDING];
uint8_t nonce[crypto_box_NONCEBYTES];
new_nonce(nonce);
memcpy(plain, &ping_id, sizeof(ping_id));
memcpy(plain + sizeof(ping_id), client_id, CLIENT_ID_SIZE);
int len = encrypt_data( public_key,
dht->c->self_secret_key,
nonce,
plain,
sizeof(ping_id) + CLIENT_ID_SIZE,
encrypt );
if (len != sizeof(ping_id) + CLIENT_ID_SIZE + ENCRYPTION_PADDING)
return -1;
data[0] = NET_PACKET_GET_NODES;
memcpy(data + 1, dht->c->self_public_key, CLIENT_ID_SIZE);
memcpy(data + 1 + CLIENT_ID_SIZE, nonce, crypto_box_NONCEBYTES);
memcpy(data + 1 + CLIENT_ID_SIZE + crypto_box_NONCEBYTES, encrypt, len);
return sendpacket(dht->c->lossless_udp->net, ip_port, data, sizeof(data));
}
/* Send a send nodes response. */
/* because of BINARY compatibility, the Node_format MUST BE Node4_format,
* IPv6 nodes are sent in a different message */
static int sendnodes(DHT *dht, IP_Port ip_port, uint8_t *public_key, uint8_t *client_id, uint64_t ping_id)
{
/* Check if packet is going to be sent to ourself. */
if (id_equal(public_key, dht->c->self_public_key))
return -1;
size_t Node4_format_size = sizeof(Node4_format);
uint8_t data[1 + CLIENT_ID_SIZE + crypto_box_NONCEBYTES + sizeof(ping_id)
+ Node4_format_size * MAX_SENT_NODES + ENCRYPTION_PADDING];
Node_format nodes_list[MAX_SENT_NODES];
int num_nodes = get_close_nodes(dht, client_id, nodes_list, AF_INET);
if (num_nodes == 0)
return 0;
uint8_t plain[sizeof(ping_id) + Node4_format_size * MAX_SENT_NODES];
uint8_t encrypt[sizeof(ping_id) + Node4_format_size * MAX_SENT_NODES + ENCRYPTION_PADDING];
uint8_t nonce[crypto_box_NONCEBYTES];
new_nonce(nonce);
memcpy(plain, &ping_id, sizeof(ping_id));
#ifdef TOX_ENABLE_IPV6
Node4_format *nodes4_list = (Node4_format *)(plain + sizeof(ping_id));
int i, num_nodes_ok = 0;
for (i = 0; i < num_nodes; i++) {
memcpy(nodes4_list[num_nodes_ok].client_id, nodes_list[i].client_id, CLIENT_ID_SIZE);
nodes4_list[num_nodes_ok].ip_port.port = nodes_list[i].ip_port.port;
IP *node_ip = &nodes_list[i].ip_port.ip;
if ((node_ip->family == AF_INET6) && IN6_IS_ADDR_V4MAPPED(&node_ip->ip6.in6_addr))
/* embedded IPv4-in-IPv6 address: return it in regular sendnodes packet */
nodes4_list[num_nodes_ok].ip_port.ip.uint32 = node_ip->ip6.uint32[3];
else if (node_ip->family == AF_INET)
nodes4_list[num_nodes_ok].ip_port.ip.uint32 = node_ip->ip4.uint32;
else /* shouldn't happen */
continue;
num_nodes_ok++;
}
if (num_nodes_ok < num_nodes) {
/* shouldn't happen */
num_nodes = num_nodes_ok;
}
#else
memcpy(plain + sizeof(ping_id), nodes_list, num_nodes * Node4_format_size);
#endif
int len = encrypt_data( public_key,
dht->c->self_secret_key,
nonce,
plain,
sizeof(ping_id) + num_nodes * Node4_format_size,
encrypt );
if (len == -1)
return -1;
if ((unsigned int)len != sizeof(ping_id) + num_nodes * Node4_format_size + ENCRYPTION_PADDING)
return -1;
data[0] = NET_PACKET_SEND_NODES;
memcpy(data + 1, dht->c->self_public_key, CLIENT_ID_SIZE);
memcpy(data + 1 + CLIENT_ID_SIZE, nonce, crypto_box_NONCEBYTES);
memcpy(data + 1 + CLIENT_ID_SIZE + crypto_box_NONCEBYTES, encrypt, len);
return sendpacket(dht->c->lossless_udp->net, ip_port, data, 1 + CLIENT_ID_SIZE + crypto_box_NONCEBYTES + len);
}
#ifdef TOX_ENABLE_IPV6
/* Send a send nodes response: message for IPv6 nodes */
static int sendnodes_ipv6(DHT *dht, IP_Port ip_port, uint8_t *public_key, uint8_t *client_id, uint64_t ping_id)
{
/* Check if packet is going to be sent to ourself. */
if (id_equal(public_key, dht->c->self_public_key))
return -1;
size_t Node_format_size = sizeof(Node_format);
uint8_t data[1 + CLIENT_ID_SIZE + crypto_box_NONCEBYTES + sizeof(ping_id)
+ Node_format_size * MAX_SENT_NODES + ENCRYPTION_PADDING];
Node_format nodes_list[MAX_SENT_NODES];
int num_nodes = get_close_nodes(dht, client_id, nodes_list, AF_INET6);
if (num_nodes == 0)
return 0;
uint8_t plain[sizeof(ping_id) + Node_format_size * MAX_SENT_NODES];
uint8_t encrypt[sizeof(ping_id) + Node_format_size * MAX_SENT_NODES + ENCRYPTION_PADDING];
uint8_t nonce[crypto_box_NONCEBYTES];
new_nonce(nonce);
memcpy(plain, &ping_id, sizeof(ping_id));
memcpy(plain + sizeof(ping_id), nodes_list, num_nodes * Node_format_size);
int len = encrypt_data( public_key,
dht->c->self_secret_key,
nonce,
plain,
sizeof(ping_id) + num_nodes * Node_format_size,
encrypt );
if (len == -1)
return -1;
if ((unsigned int)len != sizeof(ping_id) + num_nodes * Node_format_size + ENCRYPTION_PADDING)
return -1;
data[0] = NET_PACKET_SEND_NODES_IPV6;
memcpy(data + 1, dht->c->self_public_key, CLIENT_ID_SIZE);
memcpy(data + 1 + CLIENT_ID_SIZE, nonce, crypto_box_NONCEBYTES);
memcpy(data + 1 + CLIENT_ID_SIZE + crypto_box_NONCEBYTES, encrypt, len);
return sendpacket(dht->c->lossless_udp->net, ip_port, data, 1 + CLIENT_ID_SIZE + crypto_box_NONCEBYTES + len);
}
#endif
static int handle_getnodes(void *object, IP_Port source, uint8_t *packet, uint32_t length)
{
DHT *dht = object;
uint64_t ping_id;
if (length != ( 1 + CLIENT_ID_SIZE + crypto_box_NONCEBYTES
+ sizeof(ping_id) + CLIENT_ID_SIZE + ENCRYPTION_PADDING ))
return 1;
/* Check if packet is from ourself. */
if (id_equal(packet + 1, dht->c->self_public_key))
return 1;
uint8_t plain[sizeof(ping_id) + CLIENT_ID_SIZE];
int len = decrypt_data( packet + 1,
dht->c->self_secret_key,
packet + 1 + CLIENT_ID_SIZE,
packet + 1 + CLIENT_ID_SIZE + crypto_box_NONCEBYTES,
sizeof(ping_id) + CLIENT_ID_SIZE + ENCRYPTION_PADDING,
plain );
if (len != sizeof(ping_id) + CLIENT_ID_SIZE)
return 1;
memcpy(&ping_id, plain, sizeof(ping_id));
sendnodes(dht, source, packet + 1, plain + sizeof(ping_id), ping_id);
#ifdef TOX_ENABLE_IPV6
sendnodes_ipv6(dht, source, packet + 1, plain + sizeof(ping_id),
ping_id); /* TODO: prevent possible amplification attacks */
#endif
//send_ping_request(dht, source, packet + 1); /* TODO: make this smarter? */
return 0;
}
static int handle_sendnodes(void *object, IP_Port source, uint8_t *packet, uint32_t length)
{
DHT *dht = object;
uint64_t ping_id;
uint32_t cid_size = 1 + CLIENT_ID_SIZE;
cid_size += crypto_box_NONCEBYTES + sizeof(ping_id) + ENCRYPTION_PADDING;
size_t Node4_format_size = sizeof(Node4_format);
if (length > (cid_size + Node4_format_size * MAX_SENT_NODES) ||
((length - cid_size) % Node4_format_size) != 0 ||
(length < cid_size + Node4_format_size))
return 1;
uint32_t num_nodes = (length - cid_size) / Node4_format_size;
uint8_t plain[sizeof(ping_id) + Node4_format_size * MAX_SENT_NODES];
int len = decrypt_data(
packet + 1,
dht->c->self_secret_key,
packet + 1 + CLIENT_ID_SIZE,
packet + 1 + CLIENT_ID_SIZE + crypto_box_NONCEBYTES,
sizeof(ping_id) + num_nodes * Node4_format_size + ENCRYPTION_PADDING, plain );
if ((unsigned int)len != sizeof(ping_id) + num_nodes * Node4_format_size)
return 1;
memcpy(&ping_id, plain, sizeof(ping_id));
if (!is_gettingnodes(dht, source, ping_id))
return 1;
uint32_t i;
Node_format nodes_list[MAX_SENT_NODES];
#ifdef TOX_ENABLE_IPV6
Node4_format *nodes4_list = (Node4_format *)(plain + sizeof(ping_id));
uint32_t num_nodes_ok = 0;
for (i = 0; i < num_nodes; i++)
if ((nodes4_list[i].ip_port.ip.uint32 != 0) && (nodes4_list[i].ip_port.ip.uint32 != (uint32_t)~0)) {
memcpy(nodes_list[num_nodes_ok].client_id, nodes4_list[i].client_id, CLIENT_ID_SIZE);
nodes_list[num_nodes_ok].ip_port.ip.family = AF_INET;
nodes_list[num_nodes_ok].ip_port.ip.ip4.uint32 = nodes4_list[i].ip_port.ip.uint32;
nodes_list[num_nodes_ok].ip_port.port = nodes4_list[i].ip_port.port;
num_nodes_ok++;
}
if (num_nodes_ok < num_nodes) {
/* shouldn't happen */
num_nodes = num_nodes_ok;
}
#else
memcpy(nodes_list, plain + sizeof(ping_id), num_nodes * sizeof(Node_format));
#endif
addto_lists(dht, source, packet + 1);
for (i = 0; i < num_nodes; ++i) {
send_ping_request(dht->ping, nodes_list[i].ip_port, nodes_list[i].client_id);
returnedip_ports(dht, nodes_list[i].ip_port, nodes_list[i].client_id, packet + 1);
}
return 0;
}
#ifdef TOX_ENABLE_IPV6
static int handle_sendnodes_ipv6(void *object, IP_Port source, uint8_t *packet, uint32_t length)
{
DHT *dht = object;
uint64_t ping_id;
uint32_t cid_size = 1 + CLIENT_ID_SIZE;
cid_size += crypto_box_NONCEBYTES + sizeof(ping_id) + ENCRYPTION_PADDING;
size_t Node_format_size = sizeof(Node_format);
if (length > (cid_size + Node_format_size * MAX_SENT_NODES) ||
((length - cid_size) % Node_format_size) != 0 ||
(length < cid_size + Node_format_size))
return 1;
uint32_t num_nodes = (length - cid_size) / Node_format_size;
uint8_t plain[sizeof(ping_id) + Node_format_size * MAX_SENT_NODES];
int len = decrypt_data(
packet + 1,
dht->c->self_secret_key,
packet + 1 + CLIENT_ID_SIZE,
packet + 1 + CLIENT_ID_SIZE + crypto_box_NONCEBYTES,
sizeof(ping_id) + num_nodes * Node_format_size + ENCRYPTION_PADDING, plain );
if ((unsigned int)len != sizeof(ping_id) + num_nodes * Node_format_size)
return 1;
memcpy(&ping_id, plain, sizeof(ping_id));
if (!is_gettingnodes(dht, source, ping_id))
return 1;
uint32_t i;
Node_format nodes_list[MAX_SENT_NODES];
memcpy(nodes_list, plain + sizeof(ping_id), num_nodes * sizeof(Node_format));
addto_lists(dht, source, packet + 1);
for (i = 0; i < num_nodes; ++i) {
send_ping_request(dht->ping, nodes_list[i].ip_port, nodes_list[i].client_id);
returnedip_ports(dht, nodes_list[i].ip_port, nodes_list[i].client_id, packet + 1);
}
return 0;
}
#endif
/*----------------------------------------------------------------------------------*/
/*------------------------END of packet handling functions--------------------------*/
/*
* Send get nodes requests with client_id to max_num peers in list of length length
*/
static void get_bunchnodes(DHT *dht, Client_data *list, uint16_t length, uint16_t max_num, uint8_t *client_id)
{
uint64_t temp_time = unix_time();
uint32_t i, num = 0;
for (i = 0; i < length; ++i)
if (ipport_isset(&(list[i].ip_port)) && !is_timeout(temp_time, list[i].ret_timestamp, BAD_NODE_TIMEOUT)) {
getnodes(dht, list[i].ip_port, list[i].client_id, client_id);
++num;
if (num >= max_num)
return;
}
}
int DHT_addfriend(DHT *dht, uint8_t *client_id)
{
if (friend_number(dht, client_id) != -1) /* Is friend already in DHT? */
return 1;
DHT_Friend *temp;
temp = realloc(dht->friends_list, sizeof(DHT_Friend) * (dht->num_friends + 1));
if (temp == NULL)
return 1;
dht->friends_list = temp;
memset(&dht->friends_list[dht->num_friends], 0, sizeof(DHT_Friend));
memcpy(dht->friends_list[dht->num_friends].client_id, client_id, CLIENT_ID_SIZE);
dht->friends_list[dht->num_friends].NATping_id = ((uint64_t)random_int() << 32) + random_int();
++dht->num_friends;
get_bunchnodes(dht, dht->close_clientlist, LCLIENT_LIST, MAX_FRIEND_CLIENTS, client_id);/*TODO: make this better?*/
return 0;
}
int DHT_delfriend(DHT *dht, uint8_t *client_id)
{
uint32_t i;
DHT_Friend *temp;
for (i = 0; i < dht->num_friends; ++i) {
/* Equal */
if (id_equal(dht->friends_list[i].client_id, client_id)) {
--dht->num_friends;
if (dht->num_friends != i) {
memcpy( dht->friends_list[i].client_id,
dht->friends_list[dht->num_friends].client_id,
CLIENT_ID_SIZE );
}
if (dht->num_friends == 0) {
free(dht->friends_list);
dht->friends_list = NULL;
return 0;
}
temp = realloc(dht->friends_list, sizeof(DHT_Friend) * (dht->num_friends));
if (temp == NULL)
return 1;
dht->friends_list = temp;
return 0;
}
}
return 1;
}
/* TODO: Optimize this. */
int DHT_getfriendip(DHT *dht, uint8_t *client_id, IP_Port *ip_port)
{
uint32_t i, j;
uint64_t temp_time = unix_time();
ip_reset(&ip_port->ip);
ip_port->port = 0;
for (i = 0; i < dht->num_friends; ++i) {
/* Equal */
if (id_equal(dht->friends_list[i].client_id, client_id)) {
for (j = 0; j < MAX_FRIEND_CLIENTS; ++j) {
if (id_equal(dht->friends_list[i].client_list[j].client_id, client_id)
&& !is_timeout(temp_time, dht->friends_list[i].client_list[j].timestamp, BAD_NODE_TIMEOUT)) {
*ip_port = dht->friends_list[i].client_list[j].ip_port;
return 1;
}
}
return 0;
}
}
return -1;
}
/* Ping each client in the "friends" list every PING_INTERVAL seconds. Send a get nodes request
* every GET_NODE_INTERVAL seconds to a random good node for each "friend" in our "friends" list.
*/
static void do_DHT_friends(DHT *dht)
{
uint32_t i, j;
uint64_t temp_time = unix_time();
uint32_t rand_node;
uint32_t index[MAX_FRIEND_CLIENTS];
for (i = 0; i < dht->num_friends; ++i) {
uint32_t num_nodes = 0;
for (j = 0; j < MAX_FRIEND_CLIENTS; ++j) {
/* If node is not dead. */
if (!is_timeout(temp_time, dht->friends_list[i].client_list[j].timestamp, Kill_NODE_TIMEOUT)) {
if ((dht->friends_list[i].client_list[j].last_pinged + PING_INTERVAL) <= temp_time) {
send_ping_request(dht->ping, dht->friends_list[i].client_list[j].ip_port,
dht->friends_list[i].client_list[j].client_id );
dht->friends_list[i].client_list[j].last_pinged = temp_time;
}
/* If node is good. */
if (!is_timeout(temp_time, dht->friends_list[i].client_list[j].timestamp, BAD_NODE_TIMEOUT)) {
index[num_nodes] = j;
++num_nodes;
}
}
}
if (dht->friends_list[i].lastgetnode + GET_NODE_INTERVAL <= temp_time && num_nodes != 0) {
rand_node = rand() % num_nodes;
getnodes(dht, dht->friends_list[i].client_list[index[rand_node]].ip_port,
dht->friends_list[i].client_list[index[rand_node]].client_id,
dht->friends_list[i].client_id );
dht->friends_list[i].lastgetnode = temp_time;
}
}
}
/* Ping each client in the close nodes list every PING_INTERVAL seconds.
* Send a get nodes request every GET_NODE_INTERVAL seconds to a random good node in the list.
*/
static void do_Close(DHT *dht)
{
uint32_t i;
uint64_t temp_time = unix_time();
uint32_t num_nodes = 0;
uint32_t rand_node;
uint32_t index[LCLIENT_LIST];
for (i = 0; i < LCLIENT_LIST; ++i) {
/* If node is not dead. */
if (!is_timeout(temp_time, dht->close_clientlist[i].timestamp, Kill_NODE_TIMEOUT)) {
if ((dht->close_clientlist[i].last_pinged + PING_INTERVAL) <= temp_time) {
send_ping_request(dht->ping, dht->close_clientlist[i].ip_port,
dht->close_clientlist[i].client_id );
dht->close_clientlist[i].last_pinged = temp_time;
}
/* If node is good. */
if (!is_timeout(temp_time, dht->close_clientlist[i].timestamp, BAD_NODE_TIMEOUT)) {
index[num_nodes] = i;
++num_nodes;
}
}
}
if (dht->close_lastgetnodes + GET_NODE_INTERVAL <= temp_time && num_nodes != 0) {
rand_node = rand() % num_nodes;
getnodes(dht, dht->close_clientlist[index[rand_node]].ip_port,
dht->close_clientlist[index[rand_node]].client_id,
dht->c->self_public_key );
dht->close_lastgetnodes = temp_time;
}
}
void DHT_bootstrap(DHT *dht, IP_Port ip_port, uint8_t *public_key)
{
getnodes(dht, ip_port, public_key, dht->c->self_public_key);
send_ping_request(dht->ping, ip_port, public_key);
}
int DHT_bootstrap_from_address(DHT *dht, const char *address, uint8_t ipv6enabled,
uint16_t port, uint8_t *public_key)
{
IP_Port ip_port_v64;
IP *ip_extra = NULL;
#ifdef TOX_ENABLE_IPV6
IP_Port ip_port_v4;
ip_init(&ip_port_v64.ip, ipv6enabled);
if (ipv6enabled) {
ip_port_v64.ip.family = AF_UNSPEC;
ip_reset(&ip_port_v4.ip);
ip_extra = &ip_port_v4.ip;
}
#else
ip_init(&ip_port_v64.ip, 0);
#endif
if (addr_resolve_or_parse_ip(address, &ip_port_v64.ip, ip_extra)) {
ip_port_v64.port = port;
DHT_bootstrap(dht, ip_port_v64, public_key);
#ifdef TOX_ENABLE_IPV6
if ((ip_extra != NULL) && ip_isset(ip_extra)) {
ip_port_v4.port = port;
DHT_bootstrap(dht, ip_port_v4, public_key);
}
#endif
return 1;
} else
return 0;
}
/* Send the given packet to node with client_id
*
* return -1 if failure.
*/
int route_packet(DHT *dht, uint8_t *client_id, uint8_t *packet, uint32_t length)
{
uint32_t i;
for (i = 0; i < LCLIENT_LIST; ++i) {
if (id_equal(client_id, dht->close_clientlist[i].client_id))
return sendpacket(dht->c->lossless_udp->net, dht->close_clientlist[i].ip_port, packet, length);
}
return -1;
}
/* Puts all the different ips returned by the nodes for a friend_num into array ip_portlist.
* ip_portlist must be at least MAX_FRIEND_CLIENTS big.
*
* return the number of ips returned.
* return 0 if we are connected to friend or if no ips were found.
* return -1 if no such friend.
*/
static int friend_iplist(DHT *dht, IP_Port *ip_portlist, uint16_t friend_num)
{
int num_ips = 0;
uint32_t i;
uint64_t temp_time = unix_time();
if (friend_num >= dht->num_friends)
return -1;
DHT_Friend *friend = &dht->friends_list[friend_num];
Client_data *client;
for (i = 0; i < MAX_FRIEND_CLIENTS; ++i) {
client = &(friend->client_list[i]);
if (id_equal(client->client_id, friend->client_id) && !is_timeout(temp_time, client->timestamp, BAD_NODE_TIMEOUT))
return 0;
/* If ip is not zero and node is good. */
if (ip_isset(&client->ret_ip_port.ip) && !is_timeout(temp_time, client->ret_timestamp, BAD_NODE_TIMEOUT)) {
ip_portlist[num_ips] = client->ret_ip_port;
++num_ips;
}
}
return num_ips;
}
/* Send the following packet to everyone who tells us they are connected to friend_id.
*
* return ip for friend.
* return number of nodes the packet was sent to. (Only works if more than (MAX_FRIEND_CLIENTS / 2).
*/
int route_tofriend(DHT *dht, uint8_t *friend_id, uint8_t *packet, uint32_t length)
{
int num = friend_number(dht, friend_id);
if (num == -1)
return 0;
uint32_t i, sent = 0;
IP_Port ip_list[MAX_FRIEND_CLIENTS];
int ip_num = friend_iplist(dht, ip_list, num);
if (ip_num < (MAX_FRIEND_CLIENTS / 2))
return 0;
uint64_t temp_time = unix_time();
DHT_Friend *friend = &dht->friends_list[num];
Client_data *client;
for (i = 0; i < MAX_FRIEND_CLIENTS; ++i) {
client = &friend->client_list[i];
/* If ip is not zero and node is good. */
if (ip_isset(&client->ret_ip_port.ip) && !is_timeout(temp_time, client->ret_timestamp, BAD_NODE_TIMEOUT)) {
int retval = sendpacket(dht->c->lossless_udp->net, client->ip_port, packet, length);
if ((unsigned int)retval == length)
++sent;
}
}
return sent;
}
/* Send the following packet to one random person who tells us they are connected to friend_id.
*
* return number of nodes the packet was sent to.
*/
static int routeone_tofriend(DHT *dht, uint8_t *friend_id, uint8_t *packet, uint32_t length)
{
int num = friend_number(dht, friend_id);
if (num == -1)
return 0;
DHT_Friend *friend = &dht->friends_list[num];
Client_data *client;
IP_Port ip_list[MAX_FRIEND_CLIENTS];
int n = 0;
uint32_t i;
uint64_t temp_time = unix_time();
for (i = 0; i < MAX_FRIEND_CLIENTS; ++i) {
client = &friend->client_list[i];
/* If ip is not zero and node is good. */
if (ip_isset(&client->ret_ip_port.ip) && !is_timeout(temp_time, client->ret_timestamp, BAD_NODE_TIMEOUT)) {
ip_list[n] = client->ip_port;
++n;
}
}
if (n < 1)
return 0;
int retval = sendpacket(dht->c->lossless_udp->net, ip_list[rand() % n], packet, length);
if ((unsigned int)retval == length)
return 1;
return 0;
}
/* Puts all the different ips returned by the nodes for a friend_id into array ip_portlist.
* ip_portlist must be at least MAX_FRIEND_CLIENTS big.
*
* return number of ips returned.
* return 0 if we are connected to friend or if no ips were found.
* return -1 if no such friend.
*/
int friend_ips(DHT *dht, IP_Port *ip_portlist, uint8_t *friend_id)
{
uint32_t i;
for (i = 0; i < dht->num_friends; ++i) {
/* Equal */
if (id_equal(dht->friends_list[i].client_id, friend_id))
return friend_iplist(dht, ip_portlist, i);
}
return -1;
}
/*----------------------------------------------------------------------------------*/
/*---------------------BEGINNING OF NAT PUNCHING FUNCTIONS--------------------------*/
static int send_NATping(DHT *dht, uint8_t *public_key, uint64_t ping_id, uint8_t type)
{
uint8_t data[sizeof(uint64_t) + 1];
uint8_t packet[MAX_DATA_SIZE];
int num = 0;
data[0] = type;
memcpy(data + 1, &ping_id, sizeof(uint64_t));
/* 254 is NAT ping request packet id */
int len = create_request(dht->c->self_public_key, dht->c->self_secret_key, packet, public_key, data,
sizeof(uint64_t) + 1, CRYPTO_PACKET_NAT_PING);
if (len == -1)
return -1;
if (type == 0) /* If packet is request use many people to route it. */
num = route_tofriend(dht, public_key, packet, len);
else if (type == 1) /* If packet is response use only one person to route it */
num = routeone_tofriend(dht, public_key, packet, len);
if (num == 0)
return -1;
return num;
}
/* Handle a received ping request for. */
static int handle_NATping(void *object, IP_Port source, uint8_t *source_pubkey, uint8_t *packet, uint32_t length)
{
if (length != sizeof(uint64_t) + 1)
return 1;
DHT *dht = object;
uint64_t ping_id;
memcpy(&ping_id, packet + 1, sizeof(uint64_t));
int friendnumber = friend_number(dht, source_pubkey);
if (friendnumber == -1)
return 1;
DHT_Friend *friend = &dht->friends_list[friendnumber];
if (packet[0] == NAT_PING_REQUEST) {
/* 1 is reply */
send_NATping(dht, source_pubkey, ping_id, NAT_PING_RESPONSE);
friend->recvNATping_timestamp = unix_time();
return 0;
} else if (packet[0] == NAT_PING_RESPONSE) {
if (friend->NATping_id == ping_id) {
friend->NATping_id = ((uint64_t)random_int() << 32) + random_int();
friend->hole_punching = 1;
return 0;
}
}
return 1;
}
/* Get the most common ip in the ip_portlist.
* Only return ip if it appears in list min_num or more.
* len must not be bigger than MAX_FRIEND_CLIENTS.
*
* return ip of 0 if failure.
*/
static IP NAT_commonip(IP_Port *ip_portlist, uint16_t len, uint16_t min_num)
{
IP zero;
ip_reset(&zero);
if (len > MAX_FRIEND_CLIENTS)
return zero;
uint32_t i, j;
uint16_t numbers[MAX_FRIEND_CLIENTS] = {0};
for (i = 0; i < len; ++i) {
for (j = 0; j < len; ++j) {
if (ip_equal(&ip_portlist[i].ip, &ip_portlist[j].ip))
++numbers[i];
}
if (numbers[i] >= min_num)
return ip_portlist[i].ip;
}
return zero;
}
/* Return all the ports for one ip in a list.
* portlist must be at least len long,
* where len is the length of ip_portlist.
*
* return number of ports and puts the list of ports in portlist.
*/
static uint16_t NAT_getports(uint16_t *portlist, IP_Port *ip_portlist, uint16_t len, IP ip)
{
uint32_t i;
uint16_t num = 0;
for (i = 0; i < len; ++i) {
if (ip_equal(&ip_portlist[i].ip, &ip)) {
portlist[num] = ntohs(ip_portlist[i].port);
++num;
}
}
return num;
}
static void punch_holes(DHT *dht, IP ip, uint16_t *port_list, uint16_t numports, uint16_t friend_num)
{
if (numports > MAX_FRIEND_CLIENTS || numports == 0)
return;
uint32_t i;
uint32_t top = dht->friends_list[friend_num].punching_index + MAX_PUNCHING_PORTS;
for (i = dht->friends_list[friend_num].punching_index; i != top; i++) {
/* TODO: Improve port guessing algorithm. */
uint16_t port = port_list[(i / 2) % numports] + (i / (2 * numports)) * ((i % 2) ? -1 : 1);
IP_Port pinging;
ip_copy(&pinging.ip, &ip);
pinging.port = htons(port);
send_ping_request(dht->ping, pinging, dht->friends_list[friend_num].client_id);
}
dht->friends_list[friend_num].punching_index = i;
}
static void do_NAT(DHT *dht)
{
uint32_t i;
uint64_t temp_time = unix_time();
for (i = 0; i < dht->num_friends; ++i) {
IP_Port ip_list[MAX_FRIEND_CLIENTS];
int num = friend_iplist(dht, ip_list, i);
/* If already connected or friend is not online don't try to hole punch. */
if (num < MAX_FRIEND_CLIENTS / 2)
continue;
if (dht->friends_list[i].NATping_timestamp + PUNCH_INTERVAL < temp_time) {
send_NATping(dht, dht->friends_list[i].client_id, dht->friends_list[i].NATping_id, NAT_PING_REQUEST);
dht->friends_list[i].NATping_timestamp = temp_time;
}
if (dht->friends_list[i].hole_punching == 1 &&
dht->friends_list[i].punching_timestamp + PUNCH_INTERVAL < temp_time &&
dht->friends_list[i].recvNATping_timestamp + PUNCH_INTERVAL * 2 >= temp_time) {
IP ip = NAT_commonip(ip_list, num, MAX_FRIEND_CLIENTS / 2);
if (!ip_isset(&ip))
continue;
uint16_t port_list[MAX_FRIEND_CLIENTS];
uint16_t numports = NAT_getports(port_list, ip_list, num, ip);
punch_holes(dht, ip, port_list, numports, i);
dht->friends_list[i].punching_timestamp = temp_time;
dht->friends_list[i].hole_punching = 0;
}
}
}
/*----------------------------------------------------------------------------------*/
/*-----------------------END OF NAT PUNCHING FUNCTIONS------------------------------*/
DHT *new_DHT(Net_Crypto *c)
{
if (c == NULL)
return NULL;
DHT *dht = calloc(1, sizeof(DHT));
if (dht == NULL)
return NULL;
dht->ping = new_ping(dht, c);
if (dht->ping == NULL) {
kill_DHT(dht);
return NULL;
}
dht->c = c;
networking_registerhandler(c->lossless_udp->net, NET_PACKET_GET_NODES, &handle_getnodes, dht);
networking_registerhandler(c->lossless_udp->net, NET_PACKET_SEND_NODES, &handle_sendnodes, dht);
#ifdef TOX_ENABLE_IPV6
networking_registerhandler(c->lossless_udp->net, NET_PACKET_SEND_NODES_IPV6, &handle_sendnodes_ipv6, dht);
#endif
init_cryptopackets(dht);
cryptopacket_registerhandler(c, CRYPTO_PACKET_NAT_PING, &handle_NATping, dht);
return dht;
}
void do_DHT(DHT *dht)
{
do_Close(dht);
do_DHT_friends(dht);
do_NAT(dht);
do_toping(dht->ping);
}
void kill_DHT(DHT *dht)
{
kill_ping(dht->ping);
free(dht->friends_list);
free(dht);
}
/* Get the size of the DHT (for saving). */
uint32_t DHT_size_old(DHT *dht)
{
return sizeof(dht->close_clientlist) + sizeof(DHT_Friend) * dht->num_friends;
}
/* Save the DHT in data where data is an array of size DHT_size(). */
void DHT_save_old(DHT *dht, uint8_t *data)
{
memcpy(data, dht->close_clientlist, sizeof(dht->close_clientlist));
memcpy(data + sizeof(dht->close_clientlist), dht->friends_list, sizeof(DHT_Friend) * dht->num_friends);
}
/* Load the DHT from data of size size.
*
* return -1 if failure.
* return 0 if success.
*/
int DHT_load_old(DHT *dht, uint8_t *data, uint32_t size)
{
if (size < sizeof(dht->close_clientlist)) {
#ifdef DEBUG
fprintf(stderr, "DHT_load: Expected at least %u bytes, got %u.\n", sizeof(dht->close_clientlist), size);
#endif
return -1;
}
uint32_t friendlistsize = size - sizeof(dht->close_clientlist);
if (friendlistsize % sizeof(DHT_Friend) != 0) {
#ifdef DEBUG
fprintf(stderr, "DHT_load: Expected a multiple of %u, got %u.\n", sizeof(DHT_Friend), friendlistsize);
#endif
return -1;
}
uint32_t i, j;
Client_data *client;
uint16_t friends_num = friendlistsize / sizeof(DHT_Friend);
if (friends_num != 0) {
DHT_Friend *tempfriends_list = (DHT_Friend *)(data + sizeof(dht->close_clientlist));
for (i = 0; i < friends_num; ++i) {
DHT_addfriend(dht, tempfriends_list[i].client_id);
for (j = 0; j < MAX_FRIEND_CLIENTS; ++j) {
client = &tempfriends_list[i].client_list[j];
if (client->timestamp != 0)
getnodes(dht, client->ip_port, client->client_id, tempfriends_list[i].client_id);
}
}
}
Client_data *tempclose_clientlist = (Client_data *)data;
for (i = 0; i < LCLIENT_LIST; ++i) {
if (tempclose_clientlist[i].timestamp != 0)
DHT_bootstrap(dht, tempclose_clientlist[i].ip_port,
tempclose_clientlist[i].client_id );
}
return 0;
}
/* new DHT format for load/save, more robust and forward compatible */
#define DHT_STATE_COOKIE_GLOBAL 0x159000d
#define DHT_STATE_COOKIE_TYPE 0x11ce
#define DHT_STATE_TYPE_FRIENDS 1
#define DHT_STATE_TYPE_CLIENTS 2
/* Get the size of the DHT (for saving). */
uint32_t DHT_size(DHT *dht)
{
uint32_t num = 0, i;
for (i = 0; i < LCLIENT_LIST; ++i)
if (dht->close_clientlist[i].timestamp != 0)
num++;
uint32_t size32 = sizeof(uint32_t), sizesubhead = size32 * 2;
return size32
+ sizesubhead + sizeof(DHT_Friend) * dht->num_friends
+ sizesubhead + sizeof(Client_data) * num;
}
static uint8_t *z_state_save_subheader(uint8_t *data, uint32_t len, uint16_t type)
{
uint32_t *data32 = (uint32_t *)data;
data32[0] = len;
data32[1] = (DHT_STATE_COOKIE_TYPE << 16) | type;
data += sizeof(uint32_t) * 2;
return data;
}
/* Save the DHT in data where data is an array of size DHT_size(). */
void DHT_save(DHT *dht, uint8_t *data)
{
uint32_t len;
uint16_t type;
*(uint32_t *)data = DHT_STATE_COOKIE_GLOBAL;
data += sizeof(uint32_t);
len = sizeof(DHT_Friend) * dht->num_friends;
type = DHT_STATE_TYPE_FRIENDS;
data = z_state_save_subheader(data, len, type);
memcpy(data, dht->friends_list, len);
data += len;
uint32_t num = 0, i;
for (i = 0; i < LCLIENT_LIST; ++i)
if (dht->close_clientlist[i].timestamp != 0)
num++;
len = num * sizeof(Client_data);
type = DHT_STATE_TYPE_CLIENTS;
data = z_state_save_subheader(data, len, type);
if (num) {
Client_data *clients = (Client_data *)data;
for (num = 0, i = 0; i < LCLIENT_LIST; ++i)
if (dht->close_clientlist[i].timestamp != 0)
memcpy(&clients[num++], &dht->close_clientlist[i], sizeof(Client_data));
}
data += len;
}
static int dht_load_state_callback(void *outer, uint8_t *data, uint32_t length, uint16_t type)
{
DHT *dht = outer;
uint32_t num, i, j;
switch (type) {
case DHT_STATE_TYPE_FRIENDS:
if (length % sizeof(DHT_Friend) != 0)
break;
DHT_Friend *friend_list = (DHT_Friend *)data;
num = length / sizeof(DHT_Friend);
for (i = 0; i < num; ++i) {
DHT_addfriend(dht, friend_list[i].client_id);
for (j = 0; j < MAX_FRIEND_CLIENTS; ++j) {
Client_data *client = &friend_list[i].client_list[j];
if (client->timestamp != 0)
getnodes(dht, client->ip_port, client->client_id, friend_list[i].client_id);
}
}
break;
case DHT_STATE_TYPE_CLIENTS:
if ((length % sizeof(Client_data)) != 0)
break;
num = length / sizeof(Client_data);
Client_data *client_list = (Client_data *)data;
for (i = 0; i < num; ++i)
if (client_list[i].timestamp != 0)
DHT_bootstrap(dht, client_list[i].ip_port, client_list[i].client_id);
break;
default:
fprintf(stderr, "Load state (DHT): contains unrecognized part (len %u, type %u)\n",
length, type);
}
return 0;
}
/* Load the DHT from data of size size.
*
* return -1 if failure.
* return 0 if success.
*/
int DHT_load_new(DHT *dht, uint8_t *data, uint32_t length)
{
uint32_t cookie_len = sizeof(uint32_t);
if (length > cookie_len) {
uint32_t *data32 = (uint32_t *)data;
if (data32[0] == DHT_STATE_COOKIE_GLOBAL)
return load_state(dht_load_state_callback, dht, data + cookie_len,
length - cookie_len, DHT_STATE_COOKIE_TYPE);
}
return DHT_load_old(dht, data, length);
}
/* return 0 if we are not connected to the DHT.
* return 1 if we are.
*/
int DHT_isconnected(DHT *dht)
{
uint32_t i;
uint64_t temp_time = unix_time();
for (i = 0; i < LCLIENT_LIST; ++i) {
if (!is_timeout(temp_time, dht->close_clientlist[i].timestamp, BAD_NODE_TIMEOUT))
return 1;
}
return 0;
}